A sealing device is provided which provides a strong seal closure of inlet or fill opening on packages and containers of flexible or rigid construction of all sizes and shapes.
When sealing containers holding granular, powdered, or liquid materials, it is often required that a material inlet opening be positively sealed to ensure that no product leaks out, and that no foreign body penetrates into the sealed opening to contaminate the product. When the container is filled, the sealing must be accomplished quickly, easily, and positively, and with minimum complexity in terms of operation and equipment.
Further, during the filling of containers, it is not uncommon for the seal area adjacent the opening to become contaminated with the product entering the container. This contamination has a detrimental effect on the closure integrity, thus preventing adequate sealed closure in those instances where the method of closure requires a non-contaminated seal area.
Often in sealing, adhesives must be applied during or just prior to closure, which requires an adhesive reservoir, piping, a dispenser and a control mechanism. Further, if the adhesives are applied in the area of container filling, the integrity of the adhesives can be damaged by surrounding granules, powder or other particles. Generaly, in prior types of sealing arrangements using adhesives or tape placed over a fill hole, dust, powder or other material which may come from the filling contents of the container or from the environment, interfere with the integrity of the seal. Thus, powder or granules can be adhered to a tape strip or the adhesive material rendering the seal weaker. Further, the area where the tape or adhesive is to be applied is often contaminated with powder or granules which would also interfere with the integrity of the seal even if the sealing elements were introduced after the filling procedure.
Further, often a heat energy source is required in the sealing of a container just prior to closure, in addition to a transfer mechanism, to reactivate a preapplied hot melt adhesive, or to apply a hot melt adhesive in the seal area.
Also, often when a seal is placed on a container, in the manufacturing stage, separate closure sources or equipment for positioning, activation, or operation are required to apply the seal. With the existing sealing methods, it is often required that an empty space below the closure and above the material level of the flexible container exist, for the preforming of the filled, open flexible container, for the proper operation of the sealing devices. Other existing closure limitations may require a space above the material level in the bag to be free to accommodate necessary machinery for filling. Also, often the shape of the opening is restricted due to the type of seal closures available.
An object of the invention is to provide a seal which is protected from particle or dust contamination during container filling, and at all times during the sealing operation by reducing exposure of the seal to the environment during closure.
Another object of the invention is to provide a sealing device which does not require the application of adhesives during or just prior to seal closure. A further object of the invention is to provide a seal which does not require a heat energy source at the time of sealing.
A still further object of the invention is to provide a closure which provides a positive hermetic seal.
Yet another object of the invention is to provide a seal which requires no empty space below the seal and above the material level in the flexible container.
Still another object of the inveniion is to provide a seal which allows the opening of a container to have any configuration and to have an increased opening size without altering the optimum container dimensions.
Another object of the invention is to provide a seal which can be equally effective in a dry or wet environment and in normal atmosphere or in vacuum conditions.
These objects are achieved by providing a sealing device for a container to be filled including attachment or base elements for attaching sealing elements of the sealing device to the container. Protecting elements are provided for activating the sealing elements and protecting them from the environment prior to and during transfer of the sealing elements from a filling position of the sealing elements to a sealing position of the sealing elements. Resistance elements are provided above the protecting elements and sealing elements for creating resistance when the sealing strip is activated and transferred thereby reducing exposure of the sealing surface to atmosphere during closure.
In all the embodiments, any portion of the attachment elements, sealing elements, protecting elements or resistance elements which extend across the full opening of the container in the filling position to which the sealing device is to be mounted, includes an fill hole opening. In one set of embodiments, all the elements except the sealing element includes a fill hole opening since the seal element is attached at one side of the fill hole opening and bends back 180.degree. in its fill position. The protecting element and the resistance element extend from the bend back portion of the sealing element across the fill hole openings. Where additional adhesive is Provided on the upper face of the attachment element, additional layers of the protecting elements are provided with appropriate fill hole openings. The additional Protecting elements are joined to the protecting element for the sealing element such that both adhesive areas can be exposed during a common activation. In such case the protecting element has a generally S-shaped full pattern. In one embodiment, the sealing element has a S-shaped connecting the first and second end portions of the sealing elements wherein the first end portion extends across and includes a fill hole opening. The joining S-shape of the sealing element does not extend across the fill hole openings.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.